1. Field of the Invention
The present invention relates generally to a transmission system, and in particular, to an automatic Internet access method using a digital subscriber line.
2. Description of the Related Art
An xDSL (x-Digital Subscriber Line) technology is used to provide a high-speed data service using an existing telephone line. Major xDSLs include ADSL (Asymmetrical DSL), UADSL (Universal Asymmetrical DSL), HDSL (High bit rate DSL), SDSL (Symmetrical DSL), MSDSL (Multirate Symmetrical DSL), RADSL (Rate Adaptive DSL), IDSL (ISDN (Integrated services digital network) like DSL), and VDSL (Very high DSL).
The ADSL transmits both a high-speed data service and a standard voice service through a twisted-pair copper wire. The ADSL is characterized by providing the high-speed data communication service as well as the existing telephone service, using the existing telephone line and telephone set. However, the existing modem cannot be used for both the telephone service and the data communication service. The ISDN, though it can be used for both the telephone service and the data communication service, decreases in a data rate to the half. In contrast, the ADSL uses a low frequency for the telephone service and a high frequency for the data communication service on a single telephone line, thus preventing interference and securing a data rate. The ADSL is called an asymmetrical digital subscriber line, because a data rate of a forward signal from a telephone office to a subscriber is different from a data rate of a reverse signal from the subscriber to the telephone office. Compared with the existing CATV (Cable Television) in which a forward data rate is identical to a reverse data rate and the high-speed data communication service can be supported, the ADSL is disadvantageous in that its data rate is ⅓ times lower than the data rate of the CATV. However, the ADSL is advantageous in that the data rate is constant regardless of an increase in number of the subscribers. Each subscriber can transmit data at a data rate of up to 12 Mbps (bits per second). Due to this advantage, the ADSL is generally used for the high-speed data service.
However, Internet access using the ADSL has the following problems.
First, Internet access using the ADSL depends upon the type of a modem in use. That is, an internal modem uses PPPoA (Point-to-Point Protocol over Asynchronous transfer mode) and an external modem uses PPPoE (Point-to-Point Protocol over Ethernet). Thus, the internal modem must use a telephone connection adapter (or a PPP (Point-to-Point) module basically provided in WINDOWS™ for PPP communication) in a personal computer (PC), and the external modem must use a WinPoET connection program, an NTS connection program or other connection programs.
Second, the modems have different installation methods according to their types, so it is difficult to maintain and repair the modems after installation. In the case of internal modems, each modem has a unique installation driver, so a driver proper to an operating system of the user PC must be installed during installation of the modem. After installation, an operation of linking the installed internal driver to a telephone connection adapter of the user PC must be performed. In the case of external modems, a connection program used is different depending upon an operating system of the user PC. After the external modem is installed, a PPPoE server should be searched and registered in a connection window of the user PC, for proper connection. Accordingly, the installation time is increased and the installation method is complicated. When the PPPoE server name is incorrect or a proper server name cannot be found, the modem must be reinstalled.
Third, in many cases, the Internet access using the ADSL has operation trouble due to mis-operation of a connection program by the user. According to statistics, the failure due to the mis-operation by the user accounts for 40% of the total computer failure. In the case of the external modem, the user is allowed to manipulate the connection program, causing a frequent failure due to mis-manipulation by the user. In the case of the internal modem, the user may wrongly manipulate the telephone connection adapter while using the user PC. The telephone connection adapter is a module which is installed separately from a modem device deriver. If the user, not knowing that the telephone connection adapter is used for ADSL connection, mistakenly uninstalls the telephone connection adapter module or changes the set value, the ADSL communication will get into trouble.
Fourth, an Internet access program using the ADSL requires an excessive connection time, and the user must input his or her ID (identification) and password at each access.